In the image below I have generated some isolines starting from the terrain model and I have filtered them within a certain elevation range 800 - 1500m of elevation in QGIS.

But I would like to make polygons of these areas drawn in blue. enter image description here

  • 2
    Have you seen the Contours (polygons) tool? That will probably help you.
    – Matt
    Jan 15 at 0:39
  • yes QGis but it produce lines
    – stefcud
    Jan 15 at 10:29
  • 2
    It shouldnt. Make sure you are selecting contour polygons and not contour
    – BERA
    Jan 15 at 14:17
  • However I start only from a raster
    – stefcud
    Jan 15 at 19:02
  • 1
    It is a GDAL tool native to QGIS. Processing toolbox -> GDAL -> Raster extraction -> Contour Polygons.
    – Matt
    Jan 15 at 20:55

2 Answers 2


Using standard Qgis Contour that is a front end to gdal_contour utility. The solution to draw polygons instead lines is to add these parameters in addition to the command line, -amin -amax is the range of elevation values to draw.

enter image description here


As a workaround you could use this workflow:

  1. You need to translate your Line-Geometry to a Polygon-Geometry. You could use a buffer with a very small buffersize for this. If you habe more than one Ring in the Layer you can buffer just a selected Line. Perhaps there is a better solution for this step.
  2. Now you can use the Tool deleteholes. Just select the buffer as Input and start the tool.

This workflow will just work for full rings. So it wouldnt work for the red lines in your example untill you "complete" manually the line-geometries to rings.

  • Remember that I'm start from a raster, the isolines Is not required, It's only my first attempt. I think there must be a simpler solution.
    – stefcud
    Jan 15 at 19:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.